Horton

Re: Add LZ4 compression in pg_dump

Michael Paquier <michael@paquier.xyz>

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From: Michael Paquier <michael@paquier.xyz>
To: Justin Pryzby <pryzby@telsasoft.com>
Cc: Tomas Vondra <tomas.vondra@enterprisedb.com>, gkokolatos@pm.me, shiy.fnst@fujitsu.com, pgsql-hackers@lists.postgresql.org, Rachel Heaton <rachelmheaton@gmail.com>
Date: 2023-03-10T23:00:55Z
Lists: pgsql-hackers 
On Fri, Mar 10, 2023 at 07:05:49AM -0600, Justin Pryzby wrote:
> On Thu, Mar 09, 2023 at 06:58:20PM +0100, Tomas Vondra wrote:
>> I'm a bit confused about the lz4 vs. lz4f stuff, TBH. If we switch to
>> lz4f, doesn't that mean it (e.g. restore) won't work on systems that
>> only have older lz4 version? What would/should happen if we take backup
>> compressed with lz4f, an then try restoring it on an older system where
>> lz4 does not support lz4f?
> 
> You seem to be thinking about LZ4F as a weird, new innovation I'm
> experimenting with, but compress_lz4.c already uses LZ4F for its "file"
> API.

Note: we already use lz4 frames in pg_receivewal (for WAL) and
pg_basebackup (bbstreamer).
--
Michael

Commits

  1. Advance input pointer when LZ4 compressing data

  2. Null-terminate the output buffer of LZ4Stream_gets

  3. Rework code defining default compression for dir/custom formats in pg_dump

  4. pg_dump: Use only LZ4 frame format for compression

  5. Minor comment improvements for compress_lz4

  6. Unify buffer sizes in pg_dump compression API

  7. Improve type handling in pg_dump's compress file API

  8. Improve wording in pg_dump compression docs

  9. Fix condition in pg_dump TAP test

  10. Add LZ4 compression to pg_dump

  11. Introduce a generic pg_dump compression API

  12. Prepare pg_dump internals for additional compression methods

  13. Fix behavior with pg_restore -l and compressed dumps

  14. Add 250c8ee07ed to git-blame-ignore-revs

  15. Provide test coverage in pg_dump for default behaviors with compression

  16. Switch pg_dump to use compression specifications

  17. Refactor code parsing compression option values (-Z/--compress)

  18. meson: Add some missing env settings for tests of pg_dump and pg_verifybackup

  19. Extend TAP tests of pg_dump to test for compression with gzip

  20. Clean up some dead code in pg_dump with tar format and gzip compression

  21. Add TAP test in pg_dump with --format=tar and --compress

  22. Replace BASE_BACKUP COMPRESSION_LEVEL option with COMPRESSION_DETAIL.

  23. Refactor the pg_dump zlib code from pg_backup_custom.c to a separate file,